Urinary mutagenicity has been used in occupational and epidemiological studies for over two decades as a cost-effective, general biomarker of exposure to genotoxic agents.

However, few studies have compared urinary mutagenicity to additional biomarkers determined among low-and high-exposed groups.

To address this issue, we evaluated the relationship between urinary mutagenicity and other types of biomarkers in a cross-sectional study involving 15 workers exposed to the urinary bladder carcinogen benzidine (BZ, high exposure), 15 workers exposed to BZ-dyes (low exposure), and 13 unexposed controls in Ahmedabad, India.

Urinary organics were extracted by C18/methanol and evaluated for mutagenicity in the presence of S9 in the Salmonella strain YG1024, which is a frameshift strain that overproduces acetyltransferase.

The results were compared to biomarker data reported recently from the same urine samples (Rothman et al, Proc.

Natl Acad.

Sci.

USA, 93,5084-5089,1996) that included a metabolite biomarker (the sum of the urinary levels of BZ+N-acetylbenzidine+N, N'-diacetylbenzidine) and a DNA adduct biomarker [a presumptive N- (3'-phosphodeoxyguanosin-8-yl) - N'-acetylbenzidine (C8dG-ABZ) DNA adduct in exfoliated urothelial cells]. The mean ± SE urinary mutagenicity (revertants/mumol of of creatinine) of the low-exposure (BZ-dye) workers was 8.2 ± 2.4, which was significantly different from the mean of the controls (2.8 ± 0.7, P=0. (...)